The connections between water scarcity, power generation and the federal government's promotion of nuclear power are worth reflecting on in National Water Week, held from October 21-27.

Some problems associated with nuclear power are much discussed – such as its connection to the proliferation of weapons of mass destruction. Less well known is the fact that nuclear power is the most water-hungry of all energy sources, with a single reactor consuming 35-65 million litres of water each day.

Water scarcity is already a serious problem for Australia's power-generation industry, largely because of our heavy reliance on water-guzzling coal-fired plants. Current problems in Australia's power industry resulting from water shortages include: expensive long-distance water haulage to some power plants as local supplies dwindle; reduced electrical generating capacity and output at some coal and hydro plants; higher and more volatile electricity prices; increased risks of blackouts; and intensified competition for water between power plants, agriculture, industries, and environmental flows.

Introducing nuclear power would exacerbate those problems. A December 2006 report by the Commonwealth Department of Parliamentary Services notes that the water requirements for a nuclear power station are 20-83 per cent higher than for other power stations. Moreover, those calculations do not include water consumption by uranium mines. The Roxby Downs mine in South Australia uses 35 million litres of water each day, with plans to increase this to 150 million litres each day. Mine operator BHP Billiton does not pay one cent for this water despite recording a record $17 billion profit in 2006-07.

Water outflows from nuclear power plants can damage the local environment. The U.S. Environmental Protection Agency states:

"When nuclear power plants remove water from a lake or river for steam production and cooling, fish and other aquatic life can be affected. Water pollutants, such as heavy metals and salts, build up in the water used in the nuclear power plant systems. These water pollutants, as well as the higher temperature of the water discharged from the power plant, can negatively affect water quality and aquatic life."

A report by the U.S. Nuclear Information and Resource Service details the destruction of delicate marine ecosystems and large numbers of animals, including endangered species, by nuclear power plants. Most of the damage is done by water inflow pipes, while expulsion of warm water causes further damage.

Another documented problem is 'cold stunning' - fish acclimatise to warm water but die when the reactor is taken off-line and warm water is no longer expelled. In New Jersey, local fishermen estimated that 4,000 fish died from cold stunning when a reactor was shut down.

Nuclear reactors in numerous European countries have been periodically taken off-line or operated at reduced output in recent years because of water shortages driven by climate change, drought and heat waves. Nuclear utilities have also sought and secured exemptions from operating conditions in order to discharge overheated water.

The water consumption of renewable energy sources and energy efficiency and conservation measures is negligible compared to nuclear or coal. Operating a 2,400 Watt fan heater for one hour consumes 0.01 litres of water if wind is the energy source, 0.26 litres if solar is the energy source, 4.5 litres if coal is the energy source, or 5.5 litres if nuclear power is the energy source.

Tim Flannery, the 2007 Australian of the Year, notes that hastening the uptake of renewable energy sources such as wind, solar, and geothermal 'hot rocks' will help ease the water crisis as well as reducing greenhouse gas emissions - a win-win outcome.

Globally, there is another compelling reason to ensure that decisions on water allocation - including its use in energy production - are made wisely and equitably. Limited access to water is already contributing to armed conflicts ('water wars') in a number of places around the globe. UN Secretary-General Ban Ki-moon recently noted that shortages of food and water in sub-Saharan Africa were a precursor to the current tragic violence in Darfur. The problem goes "far beyond Darfur", he warned, as many other places are now suffering water shortages.

Australia can ill-afford to replace one thirsty industry, coal, with an even thirstier one, nuclear power.

Dr Sue Wareham became involved in MAPW over 20 years ago out of a "horror at the destructive capacity of a single nuclear weapon." Sue believes that her work through MAPW is fundamental to her commitment to the protection of human life and the improvement of human well-being.